NASA Contractor Report 189723

Pilot Weather Advisor

(NASA-CR-189723) PILOT WEATHER

AOVISOR (Vigyan Research

Associates) 4] p

N93-16692

Uncl as

W. A. Kilgore

S. Seth

ViGYAN Inc., Hampton, Virginia

N. L. Crabill

Aero Space Consultants, Newport New, Virginia

S. T. Shipley

I. Graffman

Hughes-STX, Lanhan, Maryland

J. O'Neill

NIALL Enterprises, Belmont, Wisconsin

G3/04 0139620

Contract NAS1-19250

November 1992

N/ A

National Aeronautics and

Space Administration

Langley Research Center

Hampton, Virginia 23665-5225

TABLE OF CONTENTS

Topic Page

Tabel of Contents .......................................... i

Abstract ................................................ ii

Abbreviations ............................................ iii

Introduction ............................................. 1

PWxA System Description ................................... 1

Ground Data Processing System ............................... 2

Airport Weather and Airport Category Data ....................... 3

Radar Data .............................................. 4

Satellite Communications System .............................. 5

PWxA Airborne Processing System ............................. 6

Test Aircraft ............................................. 8

Test Area ............................................... 8

Preflight Test Scenario ...................................... 8

Flight Test .............................................. 8

June 27, 1991 Flight ....................................... 9

System Performance, June 27, 1991 Flight ....................... 11

Flight Review and Data Comparison ........................... 14

Pilot's Comments ........................................ 15

Conclusions ............................................ 16

Future ................................................ 17

References ............................................. 18

Figures ................................................ 19

Appendices ............................................. 33

Appendix A - Station Identifiers for Wisconsin Test Area ............ 33

Appendix B - PWxA Broadcast file ........................... 34

Appendix C - Surface Observation, June 27, 1991 ................. 35

Abstract

This report gives the results of the work performed by ViGYAN, Inc. to demonstrate the

Pilot Weather Advisor cockpit weather data system using a broadcast satellite communication

system. The Pilot Weather Advisor (developed under the NASA Langley Research Center Small

Business Innovation Research Program 90-1, subtopic 03.02, Aircraft Severe Weather

Environments) demonstrated that the technical problems involved with transmitting significant

amounts of weather data to an aircraft in-flight or on-the-ground via satellite are solvable with

today's technology. The Pilot Weather Advisor is an excellent solution for providing accurate

and timely weather information for aircraft.

The purpose of the Pilot Weather Advisor is to improve the safety and utility of aircraft

operations by providing automatic updates of the weather situation to the in-flight pilot in a form

that is easily understood in terms of the planned mission. Current weather detection and

dissemination systems for general aviation are not completely satisfactory. Airborne radar is

expensive, often impractical for small single engine aircraft, has a relatively short range, and

severe attenuation in heavy rain. Lightning detectors do not provide indications of precipitation

and do not give accurate ranges for lightning activity. Radio contacts with ground sources to

acquire weather data requires considerable effort; at times is impractical; and does not always

provide an adequate representation to permit strategic flight planning. The Pilot Weather Advisor

will overcome most of these disadvantages by automatically providing near real-time graphical

depictions of weather information in the aircraft via satellite communications.

In Phase I the Pilot Weather Advisor collected NWS surface observations and WSI

NOWRAD radar data four times each hour. These surface observations and radar data were

encoded into a data stream by STX in Lanham, MD and then sent via telephone communications

to the GTE satellite Earth Station in Grand Junction, CO for uplink to the GSTAR I

communications satellite. The data stream was then broadcast covering the Continental United

States area. This data stream was received by a Qualcomm satellite communications system

provided by NIALL Enterprises of Belmont, WI on-board the aircraft. The data stream was

processed and displayed on a PC/AT computer as a graphical depiction of the surface

observations and radar data for a given geographical area using the software developed by STX

in support of the FAA Pilot Advisor Weather Support System (PAWSS) program. These

graphical depictions show the Visual Hight Rules/Instrument Hight Rules (VFR/IFR) status, the

weather of reporting airports, and the current radar data for the area. The aircraft position is also

displayed to enable the pilot to determine the best course of action in the presence of hazardous

weather.

ii

Abbreviations

ASCII

ATC

CAT I

COM

DOS

FAA

FSS

ID

IFR

LIFR

MVFR

NASA

NOWRAD

NWS

PAWSS

PC/AT

PWxA

RAM

RS

SA

SP

SBIR

TV

VGA

VIP

VFR

WSI

Z

American Standard Code for Information Interchange

Air Traffic Control

Category 1 Weather Conditons

Serial Communication Port on a Personel Computer

Disk Operation System

Federal Aviation Adminstration

Flight Service Station

Identitifcation

Instrument Flight Rules

Low Instrument Flight Rules

Marginal Visual Flight Rules

National Aeronautical and Space Adminstration

Radar Data Product from WSI

National Weather Service

Pilot's Advisor Weather Support System

Personal Computer

Pilot Weather Advisor

Radom Access Memory

Record Special Airway Observation

Surface Airway Observation

Special Airway Observation

Small Business Innovation Research

Television

Video Graphics Array

Video Integrated Processor

Visual Flight Rules

commerical provider of weather data, subsidiary of Technical Application

Science Corp.

Zulu time

°.°

!11

Introduction

This report gives the results of the work performed by ViGYAN, Inc. under contract

NAS1-19250 as Phase I, of the NASA Langley Research Center Small Business Innovation

Research (SBIR) program 90-1, subtopic 03.02, Aircraft Severe Weather Environment. This

subtopic requested "Innovative concepts for an airborne weather monitoring and processing

system that will accept data from various sensor units (airborne and ground based) to provide

hazardous weather information to the pilot". In response to this request, ViGYAN proposed to

apply the results of the Pilot Automated Weather Support System to develop the Pilot Weather

Advisor. The Pilot Weather Advisor puts large amounts of weather data on-board aircraft using

a satellite communications system and displays this data to the pilot in a suitable color graphic

format.

The Phase I work was performed during January 1991 through September 1991 by

ViGYAN and its subcontractors, and is reported herein. ViGYAN is now involved in the Phase

II of the NASA SBIR program to develop and test a Pilot Weather Advisor system for

commercial service.

PWxA System Description

The purpose of the Pilot Weather Advisor (PWxA) is to improve the safety and utility of

aircraft operations. The PWxA system shown in figure 1 provides near real-time graphical

depictions of weather information in the aircraft via satellite communications. The PWxA

collects National Weather Service (NWS) Sequence Weather Reports (surface observations) and

WSI NOWRAD radar data four times each hour. These surface observations and radar data are

encoded into a broadcast data file and then sent via telephone communications to a satellite earth

station for uplink to a communications satellite. The data file is then broadcast over the

Continental United States. This data file is received by a satellite communications system onboard an aircraft. The data file is processed and displayed on a PC/AT computer as a graphical

depiction of the surface observations and radar data for a given geographical area. These

depictions show the VFRflFR status and the weather elements of reporting stations and the

current radar for the area. The aircraft position is also displayed to enable the pilot to determine

the best course of action in the presence of hazardous weather.
The PWxA depictionsarea subsetof the depictionsdevelopedin the Pilot Automated

Weather Support System (PAWSS) project. (Ref. 1) The depictions used by the PWxA included

regional data for "Airport/Station Weather", (Airport Weather), and "Airport/Station Category",

(Airport Category), a regional version of ground weather radar reflectivity "Mosaic Radar"

(Radar), and Airport/Station Identification (Station ID). The Station ID depiction is a summary

of the geographical region and is shown in figure 2. The Airport Category depiction shown in

figure 3 is a graphical display of the VFR/IFR condition at specified observation stations. The

Airport Weather depiction shown in figure 4 is a graphical display of the weather elements at

specified observation stations. The Radar depiction shown in figure 5 is a mosaic of the current

precipitation radar for a given geographical region. All the displays use color to differentiate the

different conditions of Airport Weather, Airport Category, and Radar conditions.

Ground Data Processing System

The weather data acquisition and ground processing systems were constructed by ST

Systems Corporation (STX) at its Lanham, MD facility using real-time weather data from the

NWS and WSI. New concepts and designs for the real-time data processing software and

broadcast data formats were developed for the PWxA, and operated in support of the SBIR Phase

I effort.

Ground data processing was initiated to broadcast a final data file four times per hour on

the quarter hour. The quarter hour intervals were defined as A, B, C, and D intervals with A

being the first quarter hour. Processing for the Airport Weather and Airport Category during this

SBIR Phase I effort was time consuming, and therefore started 10 minutes before the broadcast

time.

Processing for the radar data was relatively rapid. However, the WSI NOWRAD radar

for the quarter hour was not available to users until about 10 minutes after the time of

observation, the delay in delivery ranged from 9 to 11 minutes.

An overall data flow diagram for the PWxA is shown in figure 6, identifying the major

data stores at both the ground and aircraft processing segments.
Airport Weather and Airport Category Data

The PWxA Airport Weather and Airport Category data were obtained from the NWS

Sequence Weather Reports (SA, SP, or RS) referred to as surface observations. The SA and RS

reports are specific weather observations taken at designated reporting sites throughout the United

States. These observations are usually made hourly at 50 minutes past the hour and are available

within 15 minutes of the observation time. When the weather conditions are changing a special

observation (SP) is made at any time during the hour.

The surface observations are available as ASCII data from the NWS data file and are

acquired and stored "as is" in a file on an hourly basis, beginning ten minutes before broadcast

time. The data file is "frozen" temporarily four times per hour to transfer all surface observation

reports to the ground data processor. The PWxA ground data processor deciphers these SA, SP,

and RS into a broadcast file format.

For Airport Weather, shown as a diamond, the given conditions are displayed in the

PWxA depiction as the corresponding colors:

Condition

no report

no weather, ceiling z 3000 ft. or visibility :- 5 mi.

ceiling < 3000 ft.

rain or drizzle

obstruction to vision

both rain or drizzle and obstruction to vision

hazardous weather

winds > 20 kt.

Color

clear/clear

white/white

green/green

blue/white

white/yellow

blue/yellow

red

white outline

For Airport Category, shown as a circle, the given conditions are displayed in the PWxA

depiction as the corresponding colors:

Condition

no report

ceiling > 3000 ft. or visibility z 5 mi. (VFR)

ceiling :_ 3000 ft. or visibility < 5 mi. (MVFR)

ceiling < 1000 ft. or visibility < 3 mi. (IFR)

ceiling < 500 ft. or visibility < 1 mi. (LIFR)

ceiling < 200 ft. or visibility < 0.5 mi. (<CAT I)

Color

clear/clear

white

green

blue

yellow

red

3
Figure 7 showsthe a typical SA for LSE (LaCrosse,WI) and how the PWxA ground

processordeciphersanSA into StationID, Airport Category,andAirport Weather. The colors

for the PWxA depictiondifferentiatethe flying conditionssetby the FAA guideline. For the

LSE SA shownin figure 7 the Airport Category(circle) color is white andtheAirport Weather

(diamond)color is all red. An additionalfeaturenot show in figure 7 is that if the winds are

greaterthan20 knotsthe weathersymbol(diamond)is outlined in white insteadof black.

OncethesurfaceobservationshavebeendecipheredintoStationID, Airport Weather,and

Airport Category,theyarecombinedintoa *.SFXfile whichwill bemergedwith theRadardata

file andthenbroadcast.

TheStationsselectedandusedfor the PWxA are set in the ground processing system for

a given geographical region. The geographic regions for the PWxA SBIR Phase I was centered

on Dubuque, IA (DBQ). The stations used for the DBQ geographical region are listed in

Appendix A.

Radar Data

The PWxA Radar data are obtained from the WSI NOWRAD radar data. The radar data

are acquired using the usual commercial access method supported by the WX-VIEW software

of Robertson Software, Inc. The user downloads a regional mosaic radar at 320 by 240

resolution in six reflectivity levels, in the cylindrical equidistant map projection centered on the

desired station site (for Phase I Dubuque, IA). The data are then displayed on a PC/AT at the

640 by 480 resolution, and written to a flat image file. The flat image file is then processed to

create a Radar broadcast file (*.RX). The Radar broadcast file provides the WSI NOWRAD

radar data as an 80 by 60 line grid with four reflectivities.

The Radar reflectivity levels are assigned the following values based on the Video

Integrated Processor (VIP) assessments of the precipitation intensities for the given conditions

and displayed as the corresponding colors:

Condition

zero reflectivity

non-zero reflectivity, VIP levels 1 and 2

non-zero refiectivity, VIP levels 3 and 4

non-zero reflectivity, VIP levels 5 and 6

Color

Clear (not drawn)

green

yellow

red
Once the Radar (*.RX) and Airport Weather/Category (*.SFX) broadcast files are

generated they are merged together to create a final PWxA broadcast file (*.BX) A sample

PWxA broadcast file including Radar, Airport Weather, Airport Category, and Station ID is

shown as Appendix B.

Satellite Communications System

Communications satellites are positioned 22,300 miles above the equator and travel in an

orbit that is synchronized with the rotation speed of the earth. The satellites that broadcast to

North America are positioned along the equator between 55 and 140 west longitude. From

there they cast a signal over the entire Continental United States.

Current communication satellites are made up of 16/24 transponders that are roughly

similar to TV channels when used for television or other broadband distribution services. These

channels are readily divided into much narrower bandwidth segments for data uses called Single

Channel Per Carrier applications (the technology used for the PWxA).

To reach the satellite requires an earth station that uses a large, highly directional antenna

system to avoid interfering with adjacent satellites. These earth stations are used to format the

information for transmission to various transponders on satellites and to exercise the quality

control function over the entire process.

NIALL Enterprises, Inc., Belmont WI, was operating a Piper Malibu aircraft in a test

mode with a Qualcomm satellite communications system on-board. NIALL has developed a

satellite communications data link for its own proof-of-concept use to deliver air traffic

controllers' radar data to the cockpit to generate a cockpit display for collision avoidance

purposes (Ref. 2). It was a relatively simple matter to deliver weather data on this data link

instead of air traffic controllers' radar data. ViGYAN negotiated with NIALL to provide the use

of this aircraft and satellite communications system for the PWxA test flights in the Wisconsin

area. The PWxA test flights were successfully conducted using the satellite communications

system described below.

For the series of test flights, the "satellite communications chain" of elements making up

the communications system is shown in figure 8 and briefly described as follows:
, The earth station and space segment were secured from GTE Spacenet on Ku band,

(12 and 18 gigahertz), on the satellite GSTAR I located at 103 west longitude fed by

a GTE Spacenet earth station at Grand Junction, CO.

. The mobile satellite receive system mounted on the aircraft was a standard Qualcomm

OMNITRACS system currently in use on over 14,000 semi-trailer trucks operating in

North America. This system is a half duplex, two-way data (message) system using

a patented mechanically steered antenna mounted on the mobile unit. The antenna

tracks the satellite based on the received signal strength and internal software. The

antenna was mounted on the nose of the aircraft as shown in figure 9.

. The two-way OMNITRACS data system was modified to accommodate an additional

satellite broadcast (one-way) data channel from transponder #12 on which the PWxA

broadcast data file was carried at 9600 baud. Modulation and demodulation were

accomplished with ComStream high speed VSAT data modems on each end of the

satellite communications data link.

4. In the aircraft, the PWxA broadcast data were fed to the COM 1 port of an IBM PS/2

Model 30 computer for use by the PWxA airborne processing system.

5. PWxA broadcast data were delivered to the GTE Spacenet ground station at Grand

Junction, CO from STX at Lanham, MD via dial up telephone modem at 2400 baud.

PWxA Airborne Processing System

The software for the airborne processing system of PWxA has been designed for the

common PC/AT family of personal computers. This family of microprocessors provides a

reliable and cost effective platform for the reception and display of the PWxA depictions. A

serial data stream of the broadcast file is provided to the standard COM port 1 of the PC/AT at

a standard baud rate. The user control of the PWxA is provided through a standard keyboard.

The depictions developed for the PWxA by the PAWSS project are designed for a standard VGA

video, which supports 16 programmable colors in a 640 by 480 display resolution.

The PWxA broadcast data files are received and processed to generate data stores and

depictions as shown in figure 6. A complete byte-for-byte copy of the received data stream is

collected into a quarter hourly series of files with the extension *.PCK. These data are

subsequently scanned by a decoder to identify valid (error fi'ee) packets. Decoded data for the

Airport Weather and Airport Category depictions are stored in a quarter hourly series of files
with the extension*.SFM. Decodeddatafor the Radardepictions are stored in a quarter hourly

series of files with the extension *.RAD.

The *.PCK, *.SFM and *.RAD series of quarter hourly files are uniquely identified by

filenames. All data received during each quarter hour segment is logged into the latest (open)

*.PCK file and is overwritten to the latest *.SFM and *.RAD files.

The PWxA requires, at a minimum, the following personal computer characteristics:

IBM PC/AT or compatible

VGA display (640 x 480) with at least 256 kByte video memory

640 kByte RAM memory

keyboard

system disk (DOS)

The system disk is prepared for the PWxA by creation of a directory (directory path and

name are user's choice), plus two required subdirectories IMAGES and DATA with appropriate

files.

The files in the .AIMAGES subdirectory define the geographical map projection and list

of valid Station Identifiers, respectively.

The *.PCK, *.SFM, *.RAD files are the stored PWxA data which are stored for playback

and trend assessment of the depictions in the _)ATA subdirectory.

The PWxA system is then executed running the PWxA executable:

PWXA.EXE

Users must follow the on-screen prompts to provide information on the parameters desired

for COM port 1 (baud rate, parity and number of START and STOP bits). The PWxA will

initialize, open COM port 1 for data acquisition, and start operations showing the initial PWxA

introduction page. At this time, the PWxA is looking for valid user keypress or commands.

7
Test Aircraft

The aircraft utilized for the test flights was a Piper PA-46 Malibu, N711XL owned by

Dave Stauffacher, President of EXCELL INNS, Inc. of Madison, WI. The aircraft was operated

on all flights by Dave Stauffacher. A sketch of the aircraft showing the locations of the satellite

communications equipment and the on-board PC is shown in figure 10. This equipment is not

normally carried on the aircraft during flights.

Pertinent aircraft avionics include a Sperry Weather Radar, a Wx 1000 Storm Scope, an

ARNAV 50i LORAN, a VOR/DME Area Navigation System, a VFIS Electronic Moving map,

as well as the conventional VOR and NDB receivers.

Test Area

All test flight for the PWxA were conducted in the Wisconsin area as shown in figure 11.

All test flights originated form Platteville, WI (PVB). Appendix A gives all the states and their

stations included in the Wisconsin test area.

Preflight Test Scenario

Early in the day, available sources of weather information (commercial TV broadcast,

Weather Channel, telephone FSS briefing) were utilized to formulate one or several flight test

scenarios for the Wisconsin test area. The aircraft was then ferried from Madison to Grant

County Airport near Platteville, WI (PVB). At PVB, the satellite communication equipment, PC,

and display equipment were installed and checked out. The satellite communications were

established and following execution of the PWxA software through the keyboard, the current

PWxA depictions were displayed, reviewed, and compared with the previous knowledge of the

weather situation. The flight test scenario for the day was then confirmed or modified, and the

decision-to-go was made by the pilot.

Flight Test

Four complete test flights were flown with the PWxA system in June 1991. Each flight

was documented with a video recorder, voice recorder, and the PWxA broadcast data and

depictions. Because of the developmental nature of the PWxA system several changes were

8
made to improve the PWxA system between flights. A detailed analysis was conducted for all

the flights to determine the performance of the PWxA system. The June 25 and 26 flights were

VFR; the June 27 flight was IFR, with the ATC Clearance obtained via telephone from PVB, and

picked up in the air after a VFR takeoff. The last flight (June 27, 1991) is discussed in this

report.

June 27, 1991 Flight

Summary: A morning IFR flight was conducted from Platteville, WI (PVB) to

Minneapolis, MN (MSP) in Visual Meteorological Conditions with a landing at MSP, and a

return flight later that afternoon. Takeoff from PVB was at 9:09 a.m. CDT, and landing at MSP

at 10:39 a.m. CDT. The route of flight to MSP, takeoff, and landing times are shown in figure

11, along with a list of the PWxA depictions received during the flight. The aircraft path and

position data shown herein were added after the flight.

Preflight: Information indicated a line of possibly severe convective weather was in the

Wisconsin test area, stretching from southwestern through northern Minnesota. Cell movement

was 25 to 35 kt along the line; the line itself was supposed to move slowly southeast. The MSP

terminal forecast shown below, indicated a reasonable chance of success for the flight.

MSP FT 270808 C 80 BKN 1812. 11Z 25 SCT C 80 BKN 1810 CHC C 25 OVC 3TRW.

15Z 50 scr 100 SCT C 250 BKN 1915 CHC C 40 OVC 5TRW AFT 21Z. 02Z VFR

TRW

This situation was confirmed with the first depictions (13B) which were received on the

ground at about 1400Z, figure 12 and 13. VFR conditions existed along the route of flight with

the line of convective activity positioned a little farther northwest than expected. It was decided

to fly to MSP and land there if possible, using the PWxA system to monitor the development and

movement of the convective weather line.

Enroute: After a VFR takeoff at 1409Z, the IFR clearance was received from Chicago

Center to climb and maintain 8,000 feet via Rochester (RST) and then direct MSP. The Storm

Scope showed lightning activity at about 80 and 100 miles at 11 to 12 o'clock positions, even

though the aircraft was about 220 miles from the convective weather line.

9
The first depictionreceivedin the air was 13C,figure 14, at about 1430Z. This 13C

depictionshoweda furtherspreadof thestormintonorthernWI, andayellow (level 3 or 4) cell

northwestof MSP. Someyellow appearedat the southwestend of the line. The line was

betweenMSPandAlexandria(AXN), just eastof Brainerd(BRD). Somelow levelradaractivity

wasnotedin centralWisconsinthat did notappearontheNWS RadarSummaryreviewedafter

the flight.

Severaltimes theaircraft positionwasmanuallyenteredinto the systemandshownon

thedisplay. This greatly reducedtheeffort to interpretthe depiction. The approximateaircraft

positionsweredeterminedandplottedaftertheflight on the figuresin this reportasan "X".

Justbefore1445Z,theStormScopeindicatedlightningactivity at about125miles,at the

12o'clock position. This appearedto correlatewith thepositionof the line on the(13C) Radar

depiction,figure 14.

Whenthe 13D depiction,figure 15,arrivedon-boardit showedthe line about50 miles

northwestof MSP had 3 yellow squares(levels 3 and 4) whereasat 13C it had one yellow

square. It was decidedto monitor this developmentclosely. Subsequentlythe Storm Scope

showedlightning activity 30degreesleft to 20degreesrightof theairplaneheadingat 150to 200

miles.

The 14A depiction,figure 16,showedthe line directly northwestof MSP was thinning

out, and wasdividing into two parts,northeastand southwestof our line of flight, and hadnot

comecloserto MSP. No surfaceobservationswere shownwith this depiction. (It was later

foundthatthe STXgroundprocessorfor thesurfaceobservationshadfailed.) TheStormScope

showedatthat timethesameindicationsof lightningactivity at 15degreesrightat 160milesand

25 degreesright at 120miles,with no activity indicateddeadahead.

During the flight, the cloud layer on the horizon aheadwas rising steadily, and after

1500Zit roseto approximately30 degreesabovethehorizon. Soonafterthisat about59 miles

out and 12,000 feet altitude, MSP approach started vectoring the aircraft for descent into the MSP

terminal area. At about 1516Z the aircraft was under a high overcast that extended to the horizon

on the left, but above and out of the field of view to the right.

10
Whenthe 14B depiction was received at about 1515Z, figure 17, it showed that the storm

line was still 50 miles northwest of MSP, and that the yellow (levels 3 and 4) had moved

northeast to a point directly north of MSP. Some yellow did appear down to the southwest end

of the line in South Dakota. It appeared that the cells were moving along the line to the

northeast, but the line was not moving toward MSP.

The 14B depiction continued to show the low level radar activity in central to eastern

Wisconsin. The MSP Automated Terminal Information Service Kilo obtained at this time

indicted CONVECTIVE SIGMETS 19C and 20C were current. MSP 1453Z weather was 9500

scattered, 15000 scattered, estimated ceiling 20,000 broken, visibility 12 miles, temperature 84

F, dew point 69 F, wind 200 at 14 knots with the altimeter at 29.83. Because of the proximity

to landing and the active vectoring of approach control there was little opportunity to contact

Flight Service to determine the content of the SIGMET advisory. The aircraft landed at MSP

on runway llR at 1539Z in Visual Meteorological Conditions.

After landing, the PWxA system remained on, and 14D depiction was received, figure 18,

at about 1545Z. This showed that no immediate threat existed at MSP, although some red (levels

5 and 6) had appeared down to the southwest end of the line. The next depiction 15A was not

sent by STX and therefore not received. The last depiction 15B, figure 19, was received on the

ground at about 1615Z also without surface observations. This confirmed the overall trend, that

MSP was "safe" and our flight route home to PVB showed no convective activity.

System Performance, June 27, 1991 Flight

For a complete analysis of the system performance, the flight was broken down into a

discrete set of events from which it was possible to determine the errors in the system. Below

is the procedure required to obtain a depiction in the aircraft as described earlier. This procedure

is repeated every 15 minutes.

1. NWS Sequence Weather Reports are processed to obtain desired surface

observations.

. Surface observations are then assembled into Airport Weather and Airport

Category for specified stations. (*.SFX files)

11
. WSI NOWRAD radar data are assembled into Radar for the specified test area.

(*.RX files)

. The Surface observations and Radar files are then combined into a Broadcast file

and broadcast to the aircraft. (*.BX files)

St The Broadcast files are then received by the satellite receiver and sent to the onboard PC for processing. These Broadcast files when received are saved. (*.PCK

files)

6. The Received files are then processed and Displayed on the PC monitor.

By comparing each step of the procedure an estimation of the system performance can

be determined. This analysis cannot separate the system errors and possible human errors

associated with each step in the procedure. The system performance analysis was conducted for

this flight by comparing what was the original surface observation with what was displayed in

the aircraft. The analysis is broken into the following steps and deals only with the surface

observations:

1. Surface observations -- Broadcast (Ground Processing)

2. Broadcast -- Receive (Satellite Communications)

3. Receive -- Display (Airborne Processing)

4. Surface observation -- Display (Overall Performance)

The above steps cover all the aspects of the system which are the ground processing,

satellite communications, airborne processing, and an overall performance.

Because this analysis only dealt with the surface observations, the analysis was performed

only with data sets (broadcast files) that were complete with the surface observations and the

radar data as shown in Appendix B.

12
For theflight on 6-27-91, PWxA Software Version 5, the analysis results are given below:

Display

JUN27 13B mSurface Obs. -- Broadcast

Broadcast -- Receive

Receive -- Display

Overall Set Performance

Errors %Errors

10/49 20.4%

0/49 0.0%

2/49 4.1%

11/49 22.4%

JUN27 13C Surface Obs. -- Broadcast

Broadcast -- Receive

Receive -- Display

Overall Set Performance

9/49 18.4%

0/49 0.0%

6/49 12.2%

13/49 26.5%

JUN27 13D Surface Obs. -- Broadcast

Broadcast -- Receive

Receive -- Display

Overall Set Performance

9/49 18.4%

0/49 0.0%

6/49 12.2%

12/49 24.5%

JUN27 14A Surface Obs. -- Broadcast

Broadcast -- Receive

Receive -- Display

Overall Set Performance

10/49 20.4%

0/49 0.0%

49/49 100.0%

49/49 100.0%

JUN27 14B Surface Obs. -- Broadcast

Broadcast -- Receive

Receive -- Display

Overall Set Performance

10/49 20.4%

0/49 0.0%

0/49 0.0%

10/49 20.4%

Overall Flight Surface Obs. -- Broadcast

Overall Flight Broadcast -- Receive Error

Overall Flight Receive -- Display Error

19.6%

0.0%

25.7%

Overall Flight Performance Error 38.8%

Several conclusions were drawn from the above analysis. The ground processing had

some problems creating an accurate broadcast file. The process appeared to have specific

problems with -X, -BKN, -OVC, double letters in the surface observations, problems with

visibility at 5 miles, and stations reporting more than once during the hour.

The satellite communications were extremely reliable. The communications maintained

a perfect score for these flight sets.

13
For this flight theairborneprocessexperienceda completesoftwarefailure that caused

a 100%erroronthe JUN27_14Adisplay. This errorcouldbeattributedto severalfactors. The

airbornesoftwareoccasionallyrequiredarebootof theon-boardPC. This 100%errorcouldhave

occurredduringoneof thesereboots.If the100% error is ignored from this analysis, the Overall

Flight Receive -- Display Error is reduced to 7.1% and the Overall Flight Performance Error for

this flight is 23.5%.

Overall performance of the PWxA system software for this flight was considered fair.

This fair performance can be directly related to the ground processing software. The satellite and

airborne processing software performed well if the 100% error of JUN27 14A is ignored as a

possible human error. Automation of all the processes is required to avoid human errors and to

provide a very low error system.

Flight Review and Data Comparison

This section contains available NWS weather data and maps pertinent to this flight. The

maps were supplied by the FAA FSS at Patrick Henry Airport, VA (PHF), and the alphanumeric

data were supplied by STX.

National Weather Depiction: The 16Z depiction, figure 20, indicated scattered to broken

clouds along the route, with high bases (20,000 to 25,000 feet). West and north of MSP, there

was overcast at 9,000 and 11,000 feet. The existence of the convective line northwest of MSP

was not indicated. The 19Z depiction, figure 21, showed the route was VFR with scattered

clouds at 4,000 feet visibility at DBQ. A stationary front was depicted northwest of MSP.

National Radar Summary: The 1335Z, 1435Z, 1535Z, and 1635Z data, figures 22, 23,

24, and 25, generally agree with the Radar depictions displayed on-board the aircraft. The

location, intensity, and dynamic behavior as discussed earlier are well represented. However, the

activity shown in the on-board depictions in central WI and southern IA are not shown on the

National Radar Summaries.

Surface Observations: A complete listing of the surface observation for the flight are

given in Appendix C. The performance of the PWxA system in depicting the surface

observations was considered only fair because of software problems associated with the ground

14
processing system as mentioned earlier in this report. The RWF and MSP observations are

repeated below for 15Z, 16Z, and 17Z:

MSP SA 1453 95 SCT 150 SCT E200 BKN 12 095/84/69/1911/983/307 1078

RWF Missing

MSP SA 1553 100 SCT 1=200BKN 12 098/83/70/1910/984/F1=W ACCAS NW

RWF RS 1555 60 SCT E90 BKN 250 OVC 10 084/81/71/2212/980/'FE40 MVD ENE OCNL

LTGIC N

MSP SA 1652 100 SCT 1=150 BKN 200 OVC 10 093/88/71/1717G22/983

RWF SA 1651 55 SCT E95 BKN 250 OVC 10T 080/80/71/1912/979/TB17 OVHD-N

MVG NE VlRGA W-N LTGICCG NW-NE

RWF SP 1730 55 SCT 95 SCT 250 -OVC 12 2309/982/TE15 MOVD NE DRK N1=

The NWS Radar Summary supports the Radar depictions presented by the PWxA. The

RWF SA 17Z indicates that thunder began at 1617Z overhead and to the north, and was moving

northeast, with cloud-to-cloud and cloud-to-ground lightning to the northwest through the

northeast. As noted from the other data types and the experience of the flight crew, the line of

thunderstorms did not reach to MSP during this flight. For this flight the Airport Categories and

Airport Weather depiction performance were considered only fair because of the errors associated

with the ground processing as discussed earlier. In subsequent testing performed by the FAA

PAWSS project in response to the errors found in using the PWxA system, several software

changes were made by STX to improve the performance. These improvements reduce the

performance error to less than 2% for the Airport Categories and Airport Weather depiction. If

this performance capability for the PWxA system had existed during this flight, the overall

performance error would have been about 2%. It is believed that this overall error can be

reduced to significantly less than 1% in an operational system.

Pilot's Comments

The potential for the PWxA system became evident to the pilot, Dave Stauffacher. His

comments included the following:

"...It's great. The limitations on what we're doing is the quality and quantity

of the data. It's that simple. Quality is the real-timeliness of it and the

accurateness of it, because the older it gets, the less important it is. The ability

15
to get it into the airplane has been demonstrated. Software, we can do anything

with, it's just a matter of how sophisticated you want to get. So it just boils down

to what they're giving us on the other end, what the data stream looks like, and

so its great what you're doing but we obviously have to refine that so they can

turn data around very fast, because as we saw today, we had a tough time catching

up with the weather sometimes..."

"Yeah...There's so much you can do! It was Good! OK. I'm just pleased,

Good."

He indicated that the delay between getting the Radar depiction (approximately 15

minutes) was too long and he would like the option to see the actual surface observations in

alphanumeric form.

He also indicated that the PWxA system set-up used in flight must be designed for

minimum pilot workload and must be very reliable. He felt that if the display could be placed

on the instrument panel, and possibly incorporated into the electronic moving map for navigation,

it would reduce the overall workload and be very useful.

Conclusions

The PWxA system developed under the NASA SBIR program has demonstrated that the

technical problems involved in transmitting significant amounts of weather data to a general

aviation aircraft in-flight or on-the-ground via satellite are solvable with today's technology. The

potential usefulness and need for the PWxA system concept was demonstrated to all those onboard the test flights. The Pilot Weather Advisor appears to be a viable solution for providing

accurate and timely weather information for general aviation aircraft.

It must be noted that the usefulness of the Airport Category and Airport Weather

depictions to flight management were not demonstrated due to the generally VFR weather

encountered. Additional testing will be run under fall, winter, and spring conditions.

16
Future

ViGYAN Inc. has been awarded a Phase II SBIR from NASA to further develop the

PWxA system into a commercial product. The future PWxA system will have many of the same

features with additional improvements and more information.

Some of the improvements are:

° Aircraft position automatically plotted on all depictions with a history of the aircraft

track.

. Better resolution in the Radar data block size (smaller than the 8 x 8 pixels per

block).

3. A fast acting "looping" technique to permit quick trend assessment.

. Complete automation of the ground processing of the PWxA system to improve

accuracy and speed of the PWxA system.

5. Simplified control system.

6. Improved graphical depictions.

. Automatic National Severe Storms Forecast Center "Watch Boxes" overlay on any

depiction.

8. National/Regional geographical areas.

9. Improved aerodynamics and electronics of the satellite communications antenna.

10. Indication of Lightning activity on Radar depictions.

11. Trend assessment of specified airports.

This development will be a two year effort to provide a reliable and cost effective system

of providing weather information to general aviation aircraft.

17
References

Io Dash, E.R.; Crabill, N.L.: The Pilot's Automated Support System Concept (PAWSS).

Seventh International Conference Interactive Information and Processing Systems for

Meteorology, Oceanography, and Hydrology; American Meterological Society.

January 1991.

. Gates, H.M.; O'Neill, J.N.: Aeronautical Application for Reliable Mobile Satellite

Services; IEEE Vehicular Technology Conference, Satellite Technology Session, May

11-13, 1992.

18
bOo

"o<

_J0

°_

_J

._

19
Figure 2. Airport/Station Identification Depiction.

O

0 0

0

©

©

©

0

0

0

@

®

0

©

@ 0 ®

0 0

©

Figure 3. Airport Category Depiction.

2O
O

O

O

O

O

Figure 4. Airport Weather Depiction.

....!i!ii:i_!iiii!ii!iiiiii ii.....
f

Broadcast

PWxA Ground Processor

Surface

Observation_

Satellite

OeO 0000eOO O

Communications

Airborne Processor

Keyboard

Figure 6. PWxA Data Flow Diagram

SA 1948 E150 BKN 250 OVC 6TRW-H 89/72/191_Z/977/RB43

I

I white/green/11%1 white/green

blue/red _ yellow/red

fCateaorv

VFR

MVFR

IFR

I white/green/blue

_ yellow/red

I

colo 

no ceiling white

visibility> 5 mi.

LIFR

<CAT1

ceiling < 3000 ft green

visibility < 5 mi.

ceiling< lO00ft, blue

viability < 3 mi.

ceiling < 500 ft. yellow

visibility < t mi.

ceiling < 200 ft. red

viaibility< 1/2 mi. /

Weather

Mennina

Tornado tomado red

Funnel Cloud funnel cloud red

Wetempout waterspout red

T thunderstorm red

1"+ sever thunderstorm red

R rain blue

RW rain shower blue

L drizzle blue

ZR frezzJng rain red

ZL frezzing drizzle red

A hail red

IP ice pellets red

IPW ice pellets shower red

S snow red

SW snow shower red

SP snow pellets red

SG snow gains red

_lC ice crystals red ,,

Figure 7. Analysis of

[ Obstructions to Vision

ColoUr (_vmbol Meanina

Surface Observations

BD blowing dust yellow

BN blowing sand yellow

BS blowing snow yellow

BY blowing spray yellow

D dust yellow

F fog yellow

GF ground fog yellow

H haze yellow

IF ice fog yellow

smoke yellow /

Note: If any red then all

red. If no weather

then all white.

22
GSTAR I

Trensponder12

Figure 8. Satellite Communications System•

23
Figure 9. Piper Malibu Aircraft with Qualcomm Antenna Located on Nose.

Antenna Modem

Display

Keyboard

Model 30

Figure 10. Schematic of Aircraft Showing Equipment Location.

24
300-

20O

IO0

|

J

i

PVB _N

Flight Times

Takeoff @ PVB

Landing @ MSP

1409Z = 9:09CDT

1539Z = 10:39CDT

Depictions Received

13B 1400Z

13C 1430Z

13D 1445Z

14A 1500Z

14B 1515Z

14C Not Received

14D. 1545Z

15A Not recieved

15B 1615Z

Figure 11. Wisconsin Test Area, June 27, 1991 Flight.

25
© @

@ 0 o

@

Figure 12. 27JUN13B, Airport Category and Radar Depiction, 1400Z.

iSiiiiiiiii!iiiiii"'_'_

8;:i:i:i:i:_:i:i:iSi:i:i:'

::::::::::::::::::::::::::::

i:i :,:.:

::::::

0

Figure 13. 27JUN13B, Airport Weather and Radar Depiction, 1400Z.

26
O

0

Figure 14.

©

O

©

© O ®

0

©

27JUN13C, Airport Category and Radar Depiction, 1430Z.

0 © x ®

0

O 0 ©

© 0

0

@

©

©

0

Figure 15. 27JUN13D, Airport Category and Radar Depiction, 1445Z.

27
+:4

Figure 16. 27JUN14A, Airport Category and Radar Depiction, 1500Z.

O

Figure 17.

O

© ®

0 ©

©

® 0

@ 0

©

27JUN14B, Airport Category and Radar Depiction, 1515Z.

28
O

O

Figure 18.

0 0

iiiii

0 0

0 0 0

0

0 0

0 0

0

0

0

0 0 o

0

27JUN14D, Airport Category and Radar Depiction, 1545Z.

O

O

0 0

C 0

0 0 0

0

0 0

0 0

0

0

0

0

0 0 o

0

Figure 19. 27JUN15B, Airport Category and Radar Depiction, 1615Z.

29
Figure 20.

II

Weather Depiction 16Z 27 JUN 1991.

Figure 21. Weather Depiction 19Z 27 JUN 1991.

30
&

Figure 22. Radar Summary, 1335Z 27 JUN 1991.

.i I_E

Figure 23. Radar Summary, 1435Z 2"7 .TUN 1991.

31
|

|

• • e •

i

Figure 24. Radar Summary, 1535Z 27 JUN 1991.

NE

Figure 25. Radar Summary, 1635Z 27 JUN 1991.

32
Appendix A

Station Identifiers for those stations included

Dubuque, Iowa radar site (DBQ).

Illinois

CMl=Champaign

DEC=Decator

DPA=Dupage

MDW=Midway

MLl=Quad City

PIA=Peoria

RFD=Rockford

SPI =Springfield

UlN=Quincy

Indiana

FWA=Ft. Wayne

HUF=Terre Haute

IND=lndianapolis

SBN=South Bend

Nebraska

LNK=Lincoln

OMA=Omaha

Michigan

BEH=Benton Harbor

BTL=Battle Creek

GRR=Grand Rapids

I_AN=Lansing

MKG=Muskegon

PLN=Pellston

TVC=Traverse City

South Dakota

FSD=Sioux Falls

Wisconsin

AWU=Wausaw

EAU=Eau Claire

GRB=Green Bay

LSE=LaCrosse

MKE=Milwaukee

MSN=Madsion

OSH=Oshkosh

in Wisconsin test

Iowa

ALO=Waterloo

BRL=Burlington

CID=Ceder Rapids

DBQ=Dubuque

DSM=Des Moines

MCW=Mason City

OTM=Ottumwa

SUX=Sioux City

Minnesota

AXN =Alexandria

BRD=Brainerd

FRM=Fairmont

MSP=Minn./St. Paul

RST=Rochester

RWF=Red Wood Falls

area, centered on the

Kansas

TOP=Topeka

Missouri

COU=Columbia

MCl=Kansas City

STJ=St. Joseph

STL=St. Louis

33
Appendix B

PWxA broadcast "062714C.BX" on 27 JUN 91.

s300340021440C8xs30113001111002101001101001101002146056xs302250081470D3xs3032

30091480D4xs304190021010081500F6xs305180091530D6xs306200021014031540F3xs30719

0011024021560FDxs308160041014021570FExs309150061590DAxs310120071610C9xs31110

0071630CAxs3121000140616305Fxs313110041380011260F6xs314090051660D6xs315070041

01 4011670FCxs31606001101 40413700113001Exs317050031400021300F1 xs318050021730D1

xs319520011270D2xs320510021270CAxs321800A1xs322800A2xs323800A3xs324800A4xs325

800A5xs326800A6xs327800A7xs328800A8xs329800A9xs330800A 1xs331800A2xs332800A3xs

333800A4xs334800ASxs335800A6xs336800A7xs337800A8xs338800A9xs339800AAxs340800A

2xs341800A3xs342800A4xs343800A5xs344800Aexs345800ATxs346800A8xs347800A9xs3488

00AAxs349800A Bxs350800A3xs351800A4xs352800A5xs353800A6xs354800ATxs355800A8xs3

56800A9xs357800AAxs358800ABxs359800ACxs2ALO 011568xs2AUW 000072xs2AXN

00006Cxs2BEH 000054xs2BRD 011564xs2BRL 01156Cxs2BTL 041571xs2CID 01155Cxs2CMI

041669xs2COU 011573xs2DBQ 041667xs2DEC 000051xs2DPA 00005Axs2DSM

011570xs2EAU 011567xs2FRM 00006Axs2FSD 011569xs2FWA 000063xs2GRB

04166Bxs2GRR 041584xs2HUF 04167Exs21ND 04168Exs2LAN 041574xs2LNK 011578xs2LSE

000069xs2MCI 041568xs2MCW 021574xs2MDW 0415T'/xs2MKE 04156Cxs2MKG

041578xs2MLI 041672xs2MSN 04167Exs2MSP 01157Cxs2OMA 02156Axs2OSH

041579xs2OTM 01157Cxs2PIA 041569xs2PLN 0El 68Bxs2RFD 04166Cxs2RST

0B1596xs2RWF 000074xs2SBN 000068xs2SPI 04157Bxs2STJ 000076xs2STL 01157Fxs2SUX

02158Dxs2TOP 01157Fxs2TVC 04167Dxs2UIN 000071x

34
Appendix C

Surface Observations collected for 1400Z, 6-27-91

AI_O SA 1351 250 -SCT 12 141/81/7212011G19/997

BRD SA 1350 20 SCT El00 BKN 250 BKN 10 70/64/0000/979

BRL SA 1350 100 SCT 250 -BKN 7 180/78/71/2108/008/HAZY

BTL SA 1345 250 -BKN 4H 80/68/221 21015

CID SA 1353 CLR 7 155/80/73/1812]001/HAZY

CMI SA 1345 CLR 5H 77/69/2010/014

COU SA 1350 30 -SCT 250 -SCT 7 180/77/69/1809/009

DBQ SA 1352 250 SCT 5H 164/79/7212112/004

DSM SA 1351 CLR 7 143/80/71/1913/998/FEW STFRA AND FEW CI

EAU SA 1352 200 SCT 15 104/83/69/1908/986

FSD SA 1350 110 SCT 250 -OVC 15 075/80/69/1915/979/ACCAS SW-NW-NE

GRB SA 1350 150 SCT 250 -OVC 4H 135/82/72/2116G21/994

GRR RS 1350 250 -OVC 5H 193/79/68/2211/012

HUF SA 1359 30 SCT 5FH 77/71/2307/019

IND SA 1352 CLR 5H 220/78/68/2003/020NSBY LWR E-SE

I_AN SA 1352 250 -OVC 3H 201/79/69/211 21015

LNK SA 1350 150 SCT 250-SCT 15 106/81/70/2015G24/988ANND 18V24

MCI SA 1350 CLR 6H 158/80/73/1814/003/FEW CU N

MCW SA 1350 250 -BKN 12 124/81/69/1920/993

MDW SA 1345 200-BKN 6H 79/68/2311/013

MKE SA 1353 250 -OVC 4H 161/83/71/20121002

MKG SA 1350 250 -OVC 3H 190/75/68/1711/010

MLI SA 1350 CLR 3H 175/80/7212211G15/006/FEW CI SFC VSBY 5

MSN SA 1355 270 -SCT 4H 1 53/81/72/2216/000

MSP SA 1354 E150 BKN 250 OVC 12 084/83/69/2020/980/ACCAS FRMG W-NW

OMA SA 1350 250 -BKN 8 108/79/71/1916/988/HAZY

OSH SA 1355 200 -BKN 4H 83/71/2210/997

OTM SA 1350 CLR 8 164/81/71/1912/004

PIA RS 1350 250 -OVC 5H 197/77/71/1809/013

PLN SA 1350 120 SCT E180 OVC 4H 138/81/70/2322G30/994

RFD SA 1353 250 -SCT 3H 184/80/71/1913/009

RST SA 1352 250 -SCT 10 105/82/69/2121G31/987

SPI SA 1350 250 -SCT 6H 198/77/69/1810/013

STL SA 1351 250 -SCT 7 195/79/68/2010/012/FEW CU NE-S AND W

SUX SA 1350 250 -BKN 20 093/81/71/1814/983

TOP SA 1350 CLR 10 154/79/73/1910/001

"I'VC SA 1349 E150 OVC 4H 83/70/2515G21/998/BINOVC

35
Surface Observations collected for 15007., 6-27-91

ALO SA 1450 250 -SCT 10 137/84/72/1912/996/FEW AC/803 1032

BRL SA 1450 250 -BKN 10 180/81/70/1910/008/110 1008

BTL SA 1445 250 -BKN 5H 82/68/2212/015

CID SA 1450 CLR 7 155/83/74/1913/001/HAZY FEW CI E/400 1001

CMI SA 1445 15 SCT 8 80/69/2108/0t5

COU SA 1450 55 SCT 10 183/80/68/1614/010/115 1500

DBQ SA 1451 250 SCT 5H 164/82/7312110/004/003 1008

DSM SA 1452 250-SCT 8 141/83/72/2014G20/997/002 1001

EAU SA 1450 1 50 SCT 15 101/86/69/2113/985/803

FSD SA 1450 110 SCT E250 OVC 15 077/81/69/2115/979/ACCAS ALQDS/107 1081

FWA SA 1450 CLR 7 2218265123070201FEW CU/003 1100

GRB SA 1452 250 -BKN 4H 135/85/72/2216/994/FEW AC E/603 1037

GRR SA 1450 250 -OVC 5H 190/82/68/2212/011/003 1001

HUF SA 1445 E20 BKN 6H 79/72/2108/019

HUF SP 1530 M10 OVC 2F 3520/980/PHASE III TEST

IND SA 1451 CLR 6H 222/80/69/2407/020/CU FRMG E/114 1100

I_AN SA 1453 250 -OVC 4H 200/81/6912413/014/003 1007

LNK SA 1450 150 SCT 250 -SCT 15 107/85/71/2115G20/989/WND 18V24/207 1081

LSE SA 1446 250 -SCT 8 88/71/1922/990

MCI SA 1450 CLR 6H 158/82/73/1913G21/003/FEW CU/110 1100

MKE SA 1450 250 -OVC 5H 157/85,/71/2313G18/001/000 1007

MKG SA 1450 250 -OVC 3H 187/77/68/1810/009/007 1007

MLI SA 1450 55 SCT 3H 173/81/72/1812G17/005/SFC VSBY 5/005 1500

MSN SA 1455 250 -SCT 5H 153/83/73/181 2/000/603 1001

MSP SA 1453 95 SCT 150 SCT E200 BKN 12 095/84/69/1911/983/307 1078

OMA SA 1450 250 -BKN 8 11 2/83/72./1915/989/HAZY/207 1004

OTM SA 1450 CLR 8 164/83/71/1915/004/103

PIA SA 1450 250 -BKN 8 195/82/71/2010/012/108 1001

PLN SA 1450 40 SCT E150 OVC 4H 147/81/69/2711/997/314

RFD SA 1450 250 -SCT 5H 180/82/71/1914/008/000 1001

RST SA 1453 250 -SCT 10 11 2/85/69/2222G28/990/503 1008

SBN SA 1450 250 -SCT 6H 200/82/68/2314/014/FEW CU/803 1101

SPI SA 1450 250 -SCT 6H 198/79/70/1911/013/FEW CU/115 1106

STL SA 1453 250-SCT 10 197/82/66/1807/013/CU NW-N/117 1101

SUX SA 1450 250 -BKN 15 092/84/71/1918G23/983/103 1006

TOP SA 1450 CLR 10 141/83/73/1915G23/997/203

TVC SA 1445 E150 BKN 5H 64/70/2515(324/998

36
Surface Observations collected for 1600Z, 6-27-91

ALO SA 1551 250 -SCT 12 137/86/72/2012G21/996

AUW SA 1550 250 -OVC 7 123/84/71/2212/992

AXN SA 1546 E100 BKN 250 BKN 15 080/75/67/2707/978

BEH SA 1559 40 SCT 6H 86/71/2310G16/012

BRD SA 1445 20 SCT El00 BKN 250 OVC 10 71/67/0000/979

BRL SA 1550 100 SCT 250-OVC 10 180/63/71/1808/008/FEW CU

BTL SA 1545 100 SCT 250 -BKN 5H 84/67/2410/015

CID SA 1552 25 SCT 7 155/86/75/1910/001/HAZY

CMI SA 1545 15 SCT 10 82/68/2212/014

COU SA 1550 M60 BKN 10 183/81/69/1913/010

DBQ SA 1555 CLR 6H 162/85/72/2212/003

DEC SA 1545 50 SCT 6H 84/70/2010G15/015

DPA SA 1545 -X 250 SCT 4H M/M/2311G18/008/H2

DSM SA 1551 250-SCT 8 141/85/72/1815G21/997/FEW CU E

FSD SA 1550 110 SCT E250 BKN 12 081/84/70/2115G22./981/ACCAS ALQDS

FWA SA 1550 CLR 7 218/83/65/2106/019/FEW CU HAZY

GRB SA 1551 250 -SCT 5H 133/88/73/2216/994

GRR SA 1550 50 SCT 250 -OVC 6H 188/84/69/2315/010

HUF SA 1545 M20 BKN 7 81/72/2010/018

IND SA 1554 30 SCT 6H 218/83/68/2306/019/'I'CU ALQDS

I_AN SA 1550 250 -OVC 4H 196/83/69/2114/013

MCI SA 1550 CLR 6H 155/85/73/1915/002/FEW CU

MCW SA 1550 250 SCT 12 121/86/69/2018G26/992

MDW SA 1545 200 SCT 6H 85/68/2315/010

MKE SA 1551 120 SCT 250 -BKN 5H 156/88/72/2113/001

MKG SA 1550 250 -OVC 3H 187/79/69/1810/009

M LI SA 1550 CLR 4H 171/85/73/1909G 14/005/FEW AC

MSN SA 1551 250 -BKN 6H 153/86/73/2013/000

MSP SA 1553 100 SCT E200 BKN 12 098/83/70/1910/984/FEW ACCAS NW

PIA SA 1550 250 -BKN 9 194/84/69/2010/01?_/FEW CU

RFD SA 1550 CLR 6H 176/84/73/2014/007/FEW CU

RST SA 1552 250 SCT 10 115/88/70/2319/990

RWF RS 1555 60 SCT E90 BKN 250 OVC 10 084/81/71/2212/980/TE40 MVD ENE OCNL L TGIC N

SBN SA 1550 40 SCT 6H 199/85/67/1914/013

STJ SA 1555 35 SCT 7 86/72/1915/999

STL SA 1551 250 SCT 10 195/83/66/1608/012/FEW CU WND 12V18

SPI SA 1550 27 SCT 250 -SCT 8 196/81/69/1811/013/HAZY

SUX SA 1550 250 -OVC 15 092/86/72/2115/984/ACCAS DSNT N

TOP SA 1550 CLR 10 141/84/74/1914G22/997/FEW STFRA

UIN SA 1547 33 SCT 250 SCT 6H 184/82/67/1812G16/010

OMA SA 1550 250 -BKN 10 107/86/73/1815/988/SML CU E

OTM SA 1550 CLR 10 163/87/73/1913/004

OSH SA 1545 CLR 5H 88/7212013/996

37
Surface Observations collected for 1700Z, 6-27-91

ALO SA 1650 CLR 12 137/88/71/1916G21/996/FEW CI

AUW SA 1650 250 -OVC 7 127/86/70/2310/993

AXN SA 1646 60 SCT El00 BKN 250 BKN 15 085/77/67/3107/980

BEH SA 1655 40 SCT 200 -BKN 6H 87/6912208/012

BRD SA 1655 20 SCT El00 BKN 15 76/68/2703/980

BRL SA 1650 250 -OVC 10 177/84/72/2210/007/FEW CU

BTL SA 1645 40 SCT 250 -BKN 5H 87/68/2210/013

CID SA 1652 30 SCT 8 155/87/74/1913/001/HAZY

CMI SA 1645 E25 BKN 10 82/69/2108/012

COU SA 1650 33 -SCT 7 183/84/70/1412/010

DBQ SA 1652 CLR 7 162/86/73/2010/003/FEW SC AC

DEC SA 1645 50 SCT 7 87/71/2012/013

DPA SA 1645 250 -SCT 4H M/M/2511G18/008

DSM SA 1652 250 -SCT 8 140/87/72/2016G20/997/FEW CUFRA NW-N

EAU SA 1650 E150 BKN 15 106/90/71/2210/987

FSD SA 1650 110 SCT E250 BKN 12 084/86/70/2315G19/982/ACCAS W-NE

FWA SA 1650 40 SCT 7 214/87/65/2210/018

GRB SA 1650 250 -SCT 5H 133/89/72/2117G24/994

GRR SA 1650 50 SCT 250 -OVC 6H 187/87/67/2216/010

HUF SA 1646 -X 35 -SCT 150 °SCT 200 -BKN 300 -OVC 7 85/72/0000/002/TEST PHIl I AB

HUF SA C05/069

HUF SA 1700 E20 BKN 7 84/73/1510/016

IND SA 1653 34 SCT 6H 215/85/69/2009/019/FEW MDT CU

I_AN SA 1652 E250 OVC 5H 196/85/68/2313/014/FEW CU CIG P'I'LY THN

LNK SA 1650 250 -SCT 15 103/92/70/1917G25/988/WND 16V21 =

LSE SA 1645 250 -SCT 8 93/71/1922/990

MCI SA 1650 45 SCT 6H 164/87/74/1915/002

MCW SA 1650 250 SCT 12 121/89/69/1922G28/992

MDW SA 1650 40 SCT 6H 88/67/2314/010

MKE SA 1651 120 SCT 250 -SCT 6H 156189/71/2014G20/001/FEW CU

MKG SA 1650 250 -OVC 3H 187/79/68/2113/009

MLI SA 1653 27 SCT 4H 168/86/74/2207G16/004

MSN SA 1653 250-BKN 7 153/88/73/2213/000

MSP SA 1652 100 SCT E150 BKN 200 OVC 10 093/88/71/1717G22/983

OMA SA 1650 250 -SCT 10 107/89/73/1916/988/SML CU OVR BLUFFS E

OSH SA 1645 200 SCT 5H 91/72/2115/996

OTM SA 1650 CLR 10 160/89/71/1914/003/CU ALQDS

PIA SA 1650 250 -SCT 9 190/85/69/2214/011/FEW CU

PLN SA 1653 E250 OVC 5H 141/87/70/2313/995

RFD SA 1650 50 SCT 5H 176/86//3/2116/007

RST SA 1655 250 -BKN 10 115/91/69/22.19G25/990

RWF SA 1651 55 SCT E95 BKN 250 OVC 10"I" 080/80/71/1912/979/1"B17 OVHD-N

MVG NE VIRGA W°N LTGICCG NW-NE

RWF SP 1730 55 SCT 95 SCT 250 -OVC 12 2309/982/TE15 MOVD NE DRK NE

SBN SA 1650 38 SCT 250 -SCT 6H 194/87/66/2414/012

SPI SA 1650 33 SCT 250 SCT 8 191/83/68/2013/011/HAZY

STJ SA 1645 35 SCT 7 88/73/1913/998

STL SA 1652 40 SCT 250 SCT 10 191/85/66/1513/011

SUX SA 1650 250 -OVC 15 092./90/72/2313G23/964

TOP SA 1650 CLR 10 140/86/75/1912G21/997/FEW SC

"I'VC SA 1645 E150 BKN 5H 91/70/2612(322/996

UIN SA 1650 35 SCT 55 SCT 220 SCT 6H 180/65/68/1711G17/008

38

Form Approved

REPORT DOCUMENTATION PAGE O_BNo oTo4otaa

PUOilC _'et)Ortlng 0urd_n for thl, co|lectlO¢t Of infofmatlOr_ i, estlmBttN:l to average 1 hour Der _esOoose, _ncluding the time _of reviewing m,tructlon,, _earch_ng exP,t_ng date sources,

gathenng a_i mamta0nmg the da_l _q:led, and coml_elmg and rewew,ng _e coHectlon ot InformatiOn _end comment, re<_arding this I_urden estvmate or any other asoect o1 thl,

co|le_tlOn Ot tnfocmatlon, including suggestlorrs for reducing th_s OurOen to Wa, hlngton Heldquar_ecs Services. DlrectorBte ,or Information ODeratior_s and ReDort,, 1215 Jeffer_.or_

Daw, H=ghway. Suite t204, Arlington. VA 22202-4302. end to the OWf_e of Management ancl 8uOget, PaDerwork Reduction Pro _ (0704-01_), Wa,_=ngton. OC 20503

1. AGENCY USE ONLY (LEave blank) 2. REPORT DATE

November 1992

4. TITLE AND SUBTITLE

Pilot Weather Advisor

6. AUTHOR(S)

W. A. Kilgore, S. Seth, N. L. Crahill, S. T.

I. Graffman, and J. O'Neill

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

ViGYAN, Inc.

30 Research Drive

Hampton, VA 23666

g. SPONSORING/MONITORINGAGENCYNAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Langley Research Center

Hampton, VA 23681-0001

3. REPORT TYPE AND DATES COVERED

Contractor Report

5. FUNDING NUMBERS

C NAS 1-19250

WU 324-01-00

Shipley,

8. PERFORMING ORGANIZATION

REPORT NUMBER

10. SPONSORING / MONITORING

AGENCY REPORT NUMBER

NASA CR-189723

!11. SUPPLEMENTARY NOTES

Langley Technical Monitor: Bruce D. Fisher; SBIR Phase I Report

Kilgore and Seth, VIGYAN, Inc., Hampton, VA; Crabill, Aero Space Consultants,

Newport News, VA; Shipley and Graffman, Hughes-STX, Lanhan, MD; O'Neill, NIALL

Enterprises. BP]mont. WS

12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE

Unclassified - Unlimited

Subject Category 04

13. ABSTRACT (Maximum 200 words)

This report gives the results of the work performed hy ViGYAN, Inc. to demonstrate

the Pilot Weather Advisor cockpit weather data system using a broadcast satellite

communication system. The Pilot Weather Advisor (developed under the NASA Langley

Research Center Small Business Innovation Research Program 90-I, subtopic 03.02,

Aircraft Severe Weather Environments) demonstrated that the technical problems

involved with transmitting significant amount of weather data to an aircraft

in-flight or on-the-ground via satellite are solvable with today's technology.

The Pilot Weather Advisor appears to be a viable solution for providing accurate

and timely weather information for general aviation aircraft.

14. SUBJECTTERMS

Weather, Pilot, Aircraft, Satellite Communications

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

NSN 7540-01-280-5500

18. SECURITY CLASSIFICATION

OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

15 NUMBER OF PAGES

42

16. PRICE CODE

A03

20. LIMITATION OF ABSTRACT

Standard Form 298 (Rev 2-89)

Pr.,_.cr=De_ _ ANS_ %tO Z39.;5

298.102